The present invention relates generally to an electrophotographic copying machine of a type having a multi-copy mode in which the machine performs its copying operation with copying papers which are to have an image affixed thereto are automatically fed one at a time from a paper supply unit and a manual feed mode in which the machine performs its copying operation with copying papers which are to have an image affixed thereto and which are fed manually one at a time.
In general, a present-day electrophotographic copying machine is so designed that, if the operator of the machine presets a counter the number of copies which are to be made, the copying operation can be repeated in succession for a number of cycles equal to the number of copies which are to be made. At this time, the contents of the counter are displayed by a digital display unit utilizing either light emitting diodes or liquid-crystal display elements to show the number of copies being made. The method for displaying or counting the copies being made is generally based on a count-down or count-up system such as disclosed in U.S. Pat. No. 4,105,914. Some copying machines employ either a display unit capable of showing a preset number of copies to be made or a counter for counting the number of copies being made in combination with a count-down counter or a count-up counter, examples of which are disclosed in U.S. Pat. No. 4,202,622 and Japanese Laid-open Patent Publication Nos. 53-125838 and 53-127729, both being laid open to public inspection in 1978.
For enabling an image to be copied on each side of a copying paper and/or enabling a special paper to be utilizable in reproduction of an image, some conventional copying machines have a manual paper feed unit which is provided separately from an automatic paper feed unit so that the machine can be set to operate with the copying papers which are to have an image affixed thereto are manually fed from the manual paper feed unit during one period of time and with the copying papers which are to have an image affixed thereto are automatically fed from the automatic paper feed unit during another period of time.
One form of the manual paper feed unit comprises a manual feed table supported by a machine housing for pivotal movement between a closed and an opened position such that, when the table is held in the open position, the machine can be automatically set to operate under a sequence control mode with the copying paper being manually fed through the table and, at the same time, the machine can be held in condition which is ready to receive the copying papers which are manually fed one at a time. An example of this is disclosed in the U.S. Pat. No. 4,204,668.
Another form of the manual paper feed unit comprises, such as described in connection with a preferred embodiment of the present invention, a removable feed table having a signal generating element such as a magnet or an actuating projection, which removable feed table can be removably inserted or loaded in a paper supply unit so designed as to accommodate a paper cassette containing a stack of copying papers. In this construction, when the removable feed table is loaded in the machine in place of the paper cassette, the signal generating element thereby actuates a switch element to set the machine in a condition which is ready to operate with copying papers being manually fed through the removable feed table.
In any event, any one of the conventional copying machine is so designed that when the automatic paper feed unit is in operation, a counter counts the number of copies being made, and the display unit displays the number of copies actually made or left unfinished on the basis of a result of the counting operation of the counter. No conventional copying machine, even though it has a capability of accommodating copying papers which are manually supplied one at a time in addition to the capability of accommodating the paper cassette containing a stack of copying papers, has yet been provided with a means for displaying the number of copies made on the manually supplied copying papers, and accordingly, the operator of the machine has long been formed to encounter with such an inconvenience as to manually count and remember the number of copies made. This is particularly true where a number of copies, each having its opposite faces bearing respective images, are made in succession using either ordinary copying papers or special papers.